Process for the manufacture of regenerated cellulosic material



United States Patent Ofifice 3,113,828 Patented Dec. 10, 1963 3,113,828 PROCESS FOR THE MANUFACTURE OF REGEN- ERATED CELLULOSIC MATERIAL Ernst Geiger, Stecltborn, Switzerland, assignor to Chimi-otex S.A., Geneva, Switzerland, a corporation of Switzerland No Drawing. Filed Mar. 15, 1961, Ser. No. 95,783 Claims priority, application Switzerland Mar. 15, 1960 6 Claims. (Cl. 18-54) The present invention provides a process for the manufacture of synthetic materials, such as filaments, ribbons or foils of viscose, and includes also the synthetic materials obtained by the present process.

It is known that certain additives, such as poly-alkylene glycols or reaction products thereof with fatty amines, fatty alcohols, fatty acids, aromatic acids, alcohols or amines; or aliphatic monoamines or ethoxylated derivatives thereof; diamines or polyamines; quaternary ammonium compounds or heterocyclic bases; monoor dithiocarbamates, esters of phosphoric acid with alkoxylated higher fatty alcohols and many others, incorporated with the viscose or the coagulating bath or both, produce materials having a smooth surface. If, at the same time, the filaments are stretched by 50% to 120% in hot water acidified with sulphuric acid, filaments are obtained of which the outer shell is considerably widened in relation to the core. The core may even disappear altogether, and in such a case the filament consists only of a shell and becomes substantially homogenous. The swelling value of the filament decreases, while its strength and resistance to abrasion and relaxation increases.

A new type of substance has now been found that imparts the identical properties to the filament, namely adducts of polyethylene glycols and polypropylene glycols with ortho-phosphoric acid, that is to say phosphoric acid ethers.

According to the present process the decomposition of viscose is performed in the presence of an ortho-phosphoric acid ester-ether compound of the following composition:

where R is a radical selected from the group consisting of C l-l and -C H and the sum (x-l-y-l-z) ranges from 18 to 60.

There may be used ortho-phosphoric acid polyalkoxy ethers obtained by polyaddition of ethylene oxide and/ or propylene oxide on to ortho-phosphoric acid.

The additives according to the present invention may be incorporated either with the viscose or with the decomposition bath.

The invention includes also the materials of the process referred to above.

It appears that the polar structure of the compounds of the invention further enhances their effect. They are capillary active and reduce the surface tension of viscose and of the coagulating bath. They are readily soluble both in viscose and in the coagulating bath.

When a product as specified above is added to viscose, an amount of 0.05% to 0.4% thereof, calculated on the weight of viscose, is required. Preferably the addition amounts to 1.0 gram to 1.5 grams, that is to say 1.6% to 2.4%, of the amount of cellulose present in the viscose solution.

The viscose solution may contain 4% to 9% of cellulose and 4% to 11% of sodium hydroxide. The sulphidation may be carried out with 300 to 500, preferably with 350 to 500, grams of carbon disulphide per kg. of anhydrous cellulose.

The coagulating bath contains advantageously a small proportion of acid and an increased proportion of zinc sulphate. It composed of Sodium sulphate: 10%25%, preferably 15%22% Zinc sulphate: 3%15%, preferably 1%-12%.

The coagulating bath may further contain the sulphates of iron, manganese and nickel, and these salts may take the place of part of the aforementioned proportion of zinc sulphate.

The coagulating bath may have a temperature ranging from 25 to C., advantageously from 45 to 70 C. The optimum temperature for making tire cord is 55 to 65 C.

In general, the content of sulphuric acid is reduced to the point where the filament still undergoes adequate coagulation (6% to 10% When ribbons are spun in the presence of an orthophosphoric acid ether, their surface is smooth. They possess enhanced transparency so that their aspect differs from that of ribbons spun in the absence of the additives referred to above.

Foils having a smooth surface can be spun in the presence of an ortho-phosphoric acid ether and display a higher degree of curing.

The following two examples illustrate the invention.

Example 1 Alkali cellulose from linters or wood cellulose is sulphadised with 42% of carbon disulphide. The xanthate is turned into a viscose solution containing 6.5% of cellulose and 5.5% of sodium hydroxide. During this operation 0.15% of ortho-phosphoric acid polyethylene glycol ether of molecular weight 2738 is added to the viscose solution. The viscose is then filtered, deaerated, cured and at a viscosity of 50 poises and a gamma number of 48 spun through a spinneret having 1000 orifices. The coagulating bath contains, per litre, 80 grams of sulphuric acid, 50 grams of zinc sulphate and 160 grams of sodium sulphate. The spinning solution has a temperature of 5 8 C.

The filament is then stretched by 80% in a second bath heated at C., containing 8 grams of sulphuric acid per litre, and then, on a continuous spinning machine with a filament feed reel, washed until it is free from acid, desulphurized, scrooped and dried. The dry filament is wound up at a rate of 55 metres per minute. The rate at which the viscose solution is fed into the spinneret and the rates of the draw-off, stretching and reeling means are adjusted so as to produce a filament of 1650 denier having the following properties:

Strength:

When dry grams/denier- 5.5 When Wet do 3.55 When conditioned do 4.7 Elongation:

When dry percent 9.0 When Wet do 24.0 When conditioned do 9.0

The filament is excellently suitable for making tire cord.

Example 2 Alkali cellulose from linters or wood cellulose is sulphidised with 42% of carbon disulphide, and the resulting xanthate is turned into a viscose solution containing 6.5 of cellulose and 5.5% of sodium hydroxide. During the dissolution there is added to the viscose 0.15% of ortho-phosphoric acid polyethylene glycol ether of molecular Weight 890. The viscose is then filtered, deaerated, cured and at a viscosity of 50 poises and a gamma number of 50 spun on a bobbin spinning machine comprising a spinneret with 60 orifices in a coagulating bath containing, per litre, 85 grams of sulphuric acid, 160 grams of sodium sulphate and 60 grams of Zinc sulphate, at a temperature of 58 C. The distance through which the filament travels in the solution is 3 metres. The filament is stretched in the same bath by 100% with the aid of stepped rollers. On leaving the coagulating bath the filament is wound up at a rate of 60 metres per minute.

The strength of the perfectly dry filament is 3.6 grams per denier at a titre of 150; elongation 19%.

When conditioned:

Strength grams/denier 2.96 Elongation percent 21 \Vhen wet:

Strength grams/denier 1.98 Elongation percent 32 What is claimed is:

1. A process for the production of filaments, ribbons, and films from viscose which comprises coagulating the viscose in the presence of from 0.05 to 0.4% by weight of said viscose of an orthophosphoric acid ester com pound of the formula wherein R is an alkylene radical selected from the group consisting of C H and C H and the sum (x-|-y+z) is in the range of from 18 to 60.

2. The process according to claim 1 wherein R is -C H 3. The process according to claim 1 wherein R is -C H 4. The process according to claim 1 wherein said ester compound contains both said C H and C H radicals.

5. The process according to claim 1 wherein said ester compound is added to said viscose prior to said coagulation.

6. The process according to claim 1 wherein said ester compound is added to a bath in which said coagulation is carried out.

References Cited in the file of this patent UNITED STATES PATENTS 2,310,207 Bley Feb. 9, 1943 2,696,423 Dietrich Dec. 7, 1954 2,978,292 Lirnburg et al. Apr. 4, 1961 

1. A PROCESS FOR THE PRODUCTION OF FILAMENTS, RIBBONS, AND FILMS VISCOSE WHICH COMPRISES COAGULATING THE VISCOSE IN THE PRESENCE OF FROM 0.05 TO 0.4% BY WEIGHT OF SAID VISCOSE OF AN ORTHOPHOSPHORIC ACID ESTER COMPOUND OF THE FORMULA
 6. THE PROCESS ACCORDING TO CLAIM 1 WHEREIN SAID ESTER COMPOUND IS ADDED TO A BATH IN WHICH SAID COAGULATION IS CARRIED OUT. 